Question

What will happen to immune cell development if we remove thymus from neonatal mice?

• A. B-cell maturation will be impaired
• B. Both B- and T-cell maturation will be impaired
• C. T-cell maturation will be impaired
• D. No effect on B- and T-cell maturation

Hint:

The thymus is essential for T-cell maturation. Removal of the thymus during early development will impair T-cell function but will not affect B-cell maturation.

Answer 1

The Correct Option is C

Step 1: Understand the role of the thymus in immune cell development.
The thymus is an essential organ for T-cell maturation. It is the site where immature T-cells (thymocytes) undergo selection to become fully functional, mature T-cells capable of distinguishing between self and non-self.

Step 2: Role of thymus in immune system.

• T-cells: The thymus is absolutely crucial for T-cell development and maturation. If the thymus is removed in neonatal mice, T-cell maturation will be impaired, and these mice will have a weakened immune response to pathogens that rely on T-cell activity.
• B-cells: B-cell maturation occurs in the bone marrow and does not require the thymus. Although T-cells help in B-cell activation, the absence of the thymus does not affect B-cell development directly.

Step 3: Analyze the options.

• Option (1): Incorrect — B-cell maturation is not impacted by thymus removal as it occurs in the bone marrow.
• Option (2): Incorrect — Only T-cell maturation is affected, not B-cells.
• Option (3): Correct — T-cell maturation will be impaired due to the removal of the thymus.
• Option (4): Incorrect — The thymus is necessary for T-cell maturation, so its removal will impair T-cell development.

Step 4: Conclusion.
Removing the thymus from neonatal mice will impair T-cell maturation but not B-cell maturation. Hence, option (3) is correct.